312 ARTHRODIRA. 
Yetensk.-Akad. Handl. vol. xs. no. 9 (1884), p. 5, pi. ii. fig. o.— 
Lower Devonian ; Dickson Bay, Spitzbergen. [Royal State Museum, 
Stockholm.] 
The hinder portion of the head evidently of one of the Coccosteidm, 
from the Devonian of the Government of Orel, Russia, has also been 
described under the name of Siphonodus pander i, G. Fischer de 
Waldheim, Bull. Soc. Imp. Nat. Moscou, vol. xxv. (1852), pt. i. 
p. 175, pi. iii. figs. 1-3. In this specimen, the ossified parachordal 
cartilage is seen, with the tubular canal originally occupied by the 
anterior extremity of the notochord. 
The singular mandibular rami, described as follows, may also 
pertain to this family :— 
Diplognathus mirabilis , J. S. Newberry, Ann. New York Acad. 
Sci. vol. i. (1878), p. 188, and Trans. New York Acad. 
Sci. vol. v. (1885), p. 27, and Pakeoz. Fishes N. America 
(Mon. U.S. Geol. Surv. no. xvi. 1889), p. 159, pi. xi. 
figs. 1-4, pi. xii. figs. 1-3.—Cleveland Shale; Lorain Co., 
Ohio. [Columbia College, New York.] 
Family ASTEROSTEIDiE. 
An imperfectly known family, as yet incompletely definable. 
Nasal openings large and mesially placed, scarcely, if at all, in 
advance of the orbits. 
Genus A8TEROSTEXJS, Newberry. 
[Rep. Geol. Surv. Ohio, vol. ii. pt. ii. 1875, p. 35.] 
A genus comprising species of small size, known only by the 
cranial shield. Head long and narrow, flattened, having the con¬ 
stituent elements fused in the adult; orbits placed far forwards and 
forming broad notches, between which is a pair of large, oval nasal 
openings ; a pineal foramen somewhat more posteriorly. Cranial 
roof ornamented with large, rounded, stellate tubercles, very irre¬ 
gular in size and arrangement. 
This diagnosis is based upon a personal examination of the 
specimens in the Columbia College, New York, and the American 
